Replace removed os-vif-ovs job and remove grenade-skip-level

It was replaced by os-vif-ovn job.

Changes:
  .zuul.yaml

NOTE(elod.illes): the change is because patch in version
unmaintained/2024.1 included the remove of grenade job from 2023.2,
because it went to End of Life, hence the job couldn't run anymore.
So this is basically a partial backport from 2024.1, but technically
the same patch as on stable/* branches.

This patch also includes the following patch to fix the gate:

[stable-only] Remvoe grenade-skip-level from yoga

unmaintained/yoga is the last available open branch, besides,
grenade-skip-level only relevant between SLURP branches, so here it
was only experimental. So this patch simply removes it to unblock
the gate.

Depends-on: https://review.opendev.org/c/openstack/os-vif/+/798038
Change-Id: I4fc595eb51c05c4875bc94e0e812f117a35df7cf
Signed-off-by: Takashi Kajinami <kajinamit@oss.nttdata.com>
(cherry picked from commit ad91193)
(cherry picked from commit 1783a30)
(cherry picked from commit ccf3e18)
(cherry picked from commit 95c43bc)
(cherry picked from commit d7ca3d9)
(cherry picked from commit eaa65f0)
(cherry picked from commit 422d33e)

Author: kajinamit

.zuul.yaml

@@ -653,8 +653,6 @@
              - ^setup.cfg$
              - ^tools/.*$
              - ^tox.ini$
-        - grenade-skip-level:
-            irrelevant-files: *policies-irrelevant-files
         - nova-grenade-multinode:
             irrelevant-files: *policies-irrelevant-files
         - tempest-ipv6-only:
@@ -713,7 +711,7 @@
             irrelevant-files: *nova-base-irrelevant-files
         - neutron-ovs-tempest-iptables_hybrid:
             irrelevant-files: *nova-base-irrelevant-files
-        - os-vif-ovs:
+        - os-vif-ovn:
             irrelevant-files: *nova-base-irrelevant-files
         - devstack-plugin-ceph-compute-local-ephemeral:
             irrelevant-files: *nova-base-irrelevant-files